package com.xj.reggie.controller;

import com.xj.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * @Author XJ
 * @Date 2022/10/19 10:39
 * @PackageName:com.xj.reggie.controller
 * @ClassName: CommonController
 * @Description: TODO
 * @Version 1.0
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

	@Value("${reggie.path}")
	private String basePath;
	/**
	 * 文件上传
	 * @param file
	 * @return
	 */
	@PostMapping("/upload")
	public R<String> upload(MultipartFile file){
		//file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
		log.info(file.toString());

		//原始文件名
		String originalFilename = file.getOriginalFilename();
		String suffix=originalFilename.substring(originalFilename.lastIndexOf("."));

		//使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
		String fileName = UUID.randomUUID().toString()+suffix;

		//创建一个目录对象
		File dir = new File(basePath);
		//判断当前目录是否存在
		if(!dir.exists()){
			//目录不存在，需要创建
			dir.mkdirs();
		}

		try {
			//将临时文件转存到指定位置
			file.transferTo(new File(basePath+fileName));
		} catch (IOException e) {
			e.printStackTrace();
		}
		return R.success(fileName);
	}

	/**
	 * 文件下载
	 * @param name
	 * @param response
	 */
	@GetMapping("/download")
	public void download(String name, HttpServletResponse response){
		try {
			//输入流，通过输入流读取文件内容
			FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));

			//输出流，通过输出流将文件写回浏览器，在浏览器展示图片了
			ServletOutputStream outputStream = response.getOutputStream();

			response.setContentType("image/jpeg");

			int len = 0;
			byte[] bytes = new byte[1024];
			while ((len = fileInputStream.read(bytes)) != -1){
				outputStream.write(bytes,0,len);
				outputStream.flush();
			}

			//关闭资源
			outputStream.close();
			fileInputStream.close();

		} catch (Exception e) {
			e.printStackTrace();
		}

	}
}
